1. Field of the Invention
The present invention relates to an electronic component, and more particularly to an electronic component including a Sn-plated film, such as a laminated ceramic capacitor, for example.
2. Description of the Related Art
As a background technique for the present invention, for example, International Publication WO2006/134665 discloses a member on which a film having Sn as a main ingredient is formed, a film formation method and a soldering method.
If a film is formed on a terminal for a connector, a lead frame for a semiconductor integrated circuit or the like, by plating a metal that has Sn as a main ingredient and does not contain Pb, in place of plating Sn—Pb solder which has been conventionally done, from the viewpoint of environmental protection in recent years, whisker-like crystals, called whiskers, of Sn tend to develop in the film. When whiskers develop and grow, they may cause an electric short-circuit failure between adjacent electrodes. When whiskers separate from a film and scatter, the scattering whiskers become a cause of inducing a short-circuit inside and outside the equipment.
In the technique disclosed in International publication WO2006/134665, for the purpose of providing a member having a film which can suppress development of such whiskers, an intermetallic compound layer of Sn and a first metal such as Ni is formed at a grain boundary of Sn particularly in a film having Sn as a main ingredient.
However, the film disclosed in International publication WO2006/134665 cannot meet the criterion of Class 2 when conducting the following thermal shock test defined in the JEDEC Standard considered as an industrial standard.